This invention relates in general to reducing machines and more particular to a shredding unit for shredding large pieces of metal scrap.
The steel from junk automobiles, applicances, and the like is valuable for making new steel, provided it is in an acceptable condition. Steel companies prefer shredded or reduced scrap which is substantially free from impurities such as other metals, elastomers and plastics. Heretofore, shredding devices have been developed for converting automobile bodies, frames, and large appliances into relatively small fragments, but these machines have required an excessive amount of maintenance and are difficult to repair. For example, seat covers, upholstery, plastics, undercoating and the like tends to pack in the clearance areas surrounding the hammershafts and make these shafts extremely difficult to withdraw which is necessary in order to replace the hammers. The problem is compounded by the fact that the shafts are sometimes bent or otherwise distorted. Also, the hammershafts are often used to hold the rotor together in the axial direction so that once removed, the fine fits of the initial assembly are lost and the rigidity of the rotor is impaired. Furthermore, it is desirable to have the cutter bar, over which the scrap is fed into the rotor, located an optimum distance from the paths described by the hammers, but as the hammers wear this distance changes, reducing the efficiency of the machine. In addition, once the cutting edge on the cutter bar is lost, the entire bar must be replaced. Moreover, the bolts which hold the liners in place shake loose and a bolt tightening schedule must be undertaken usually once a day.